The image quality of image data generated by a digital still camera (DSC), digital video camera (DVC), scanner or the like can be arbitrarily adjusted by use of an image-retouching application included in a personal computer. The image-retouching application is generally provided with an image adjustment function of automatically adjusting image quality (or characteristics) of image data, and this image adjustment function makes it possible to readily adjust image quality of image data to be output from an output device into normal image quality. The output device of image data includes, for example, a CRT, a printer, a projector, a television receiver, and the like.
The printer driver for controlling operations of printer, which is one of output devices, is also provided with a function of automatically adjusting image quality (or characteristics) of image data, and such printer driver makes it possible to readily adjust image quality of image data to be printed into normal image quality.
Typically, the automatic image quality adjustment function performed by the image-retouching application and the like performs image quality correction based on image quality of normal image data. However, since the image data subject to image processing can be generated under a variety of conditions, the automatic image quality adjustment function may result in poor image quality if the image quality (or characteristics) of image data is equally corrected using a reference value that is designed for the normal image data.
In addition, some image data generation devices such as DSC allow image quality of image data to be arbitrarily adjusted during generation of the image data, and the user can intentionally generate image data having a predetermined image quality. If the automatic image quality adjustment function is performed on such image data, intentional image characteristics of the image data are also adjusted equally based on the reference value. Thus, there is a problem that in such cases it is impossible to obtain an output image with the user's intention reflected thereon.